Effect of L-arginine on age-dependent changes of lipid peroxidation processes and antioxidant system activity in rat tissues

The antioxidant system and lipid peroxidation processes under the L-arginine injection were investigated in experiments on the myocardium, liver and blood of rats of different age. Lipid peroxidation processes intensification and antioxidant system enzymes activity decrease in old rats was shown. A pro- and antioxidant property changes which had different specificity and depended on the tissue were investigated. It was concluded that NO-ergic link activated antioxidant protection in old rats, activates antioxidant enzymes but does not influence the antioxidant properties of tissues of young and adult rats.     

Lipid peroxidation in skeletal muscles of rats during maximum physical exertion and its correction by ionol

The maximum physical exercises lead to the activation of lipid peroxidation in rats. It is accompanied by an increase in the concentration of diene conjugates and malonic dialdehyde in skeletal muscles. Preliminary administration of ionol antioxidant, prevents these changes. The possibilities of using the antioxidant in the prevention of skeletal muscle lesion during physical exercises are discussed.     

Effect of oral methionine on blood lipid peroxidation and antioxidants in alloxan-induced diabetic rats

Supplementation of thiol compounds has been suggested to protect against the toxic effects of reduced oxygen species by contributing to the thiol pool of the cell. The present study was designed to determine whether supplementation of methionine in the diet of diabetic animals protected against the oxidative stress in diabetic pathology. Oral methionine was administered at a dosage of 330 mg/100 g feed to diabetic rats. The effect was compared with the effect of insulin administration. Levels of lipid peroxides were measured in plasma, erythrocytes, and erythrocyte membrane. Anti-oxidants were measured in plasma. Diabetic condition was associated with increased lipid peroxidation and depletion in antioxidant levels. Although methionine did not affect the level of blood glucose and some of the antioxidants, it lowered the lipid peroxide content in blood. Erythrocyte lipid peroxidation activity was unaffected by methionine treatment. Administration of insulin lowered both plasma and erythrocyte lipid peroxide levels.     

Effect of ionol on the stomach lesion in rats during immobilization stress

Intragastric administration of the antioxidant ionol (50 mg/kg/a day) for 7 days did not prevent the formation of ulcers or massive hemorrhages to the gastric mucosa in immobilized animals, increased the number of petechiae and lowered that of erosions. In this case the parietal pH increased in the stomach and dropped in the remaining divisions of the alimentary tract. The combined action of stress and ionol brought about marked hypocoagulation. Ionol exerted a protective action on the stress-induced activation of lipid peroxidation in the stomach but did not produce any such effect on the liver.     

Effect of chronic fluorosis on lipid peroxidation and histology of kidney tissues in first- and second-generation rats

This experiment was designed to investigate the lipid peroxidation and histological effects of chronic fluorosis on first- and second-generation rat kidney tissues. Sixteen virgin female Wistar rats were mated with eight males (2∶1) for approx 12 h to obtain first-generation rats. Mating was confirmed by the presence of sperm in vaginal smears. Sperm in vaginal smears was observed in 10 of 16 rats (d 0). These rats were identified as pregnant and included in this experiment. Pregnant rats were divided into two experimental groups (control and fluoride-supplemented), each containing five rats. The pregnant rats in the fluoride-supplemented group were exposed to 30 mg/L sodium fluoride (NaF) in commercial drinking water containing 0.07 mg/L NaF throughout the gestation and the lactation periods. After the lactation period, young animals (first generation [F1]) were exposed to the same amount of NaF in drinking water for 4 mo. At the end of the 4-mo experimental period, nine randomly chosen male rats (F1) were sacrificed, and the kidneys were removed for the histological and lipid peroxidation examinations. The remaining eight female rats were mated with four males (2∶1) for approx 12 h to obtain second-generation rats. Six female were identified as pregnant, and treated similarly throughout the gestation and the lactation periods. After the lactation period, the young male rats (second-generation male rats [F2]) were also treated similarly for 4 mo. At the end of the 4-mo experimental period, nine randomly chosen male rats (F2) were sacrificed, and the kidneys were removed for the histological and lipid peroxidation examinations. The rats in the control groups underwent the same procedure without NaF supplementation. It was found that the plasma fluoride and kidney TBARS levels of fluoride-supplemented F1 and F2 rats were higher than controls. Hydropic epithelial cell degenerations and moderate tubular dilatation were observed in some proximal and distal tubules. There were markedly focal mononuclear cell infiltrations and hemorrhage at some areas of the interstitium, especially at the corticomedullar junction. Mononuclear cell infiltrations were also evident in some peritubular and perivascular areas. Most of the vascular structures were congestive. Many Bowman capsules were narrowed. The severe degenerative changes in most of the shrunken glomerules and vascular congestion were also observed. It is concluded that chronic fluorosis causes a marked destruction in kidney tissues of F1 and F2 rats by causing lipid peroxidation. Department of Orthopedics, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey     

Features of lipid peroxidation in brain and liver tissues from aging rats under stress

The lipid peroxidation (LPO) level between in the adult and old rats brain and liver was determined as to be essentially undiffering. Stress activated the LPO independence the age of animals and tissues investigated. The concentration changes of LPO products testify to it. In the adult rats under the stress capability of tissues to induction in vitro ferment and ascorbat-depending LPO, in comparison with the control, decreases, at old--does not change in the brain and considerably grows in the liver. Stress is accompanied by an oppression of Na, K-ATP-ase PM activity of hepatocytes, more expressed in the old animals.     

Effect of whole-body gamma irradiation on lipid peroxidation in rat tissues

In this work, we studied the influence of wholebody gamma irradiation (800 rads) upon malonaldehyde (MDA) content in plasma, erythrocyte, brain, heart, lung, kidney, spleen, liver, thymus and bone marrow. MDA levels were increased in all studied samples, except lung; the highest increases were observed in the most radiosensitive organs (bone marrow, thymus, spleen) and not in those continuously exposed to high concentrations of molecular oxygen (lungs, erythrocytes). Comparison of the variations of MDA levels in plasma, kidneys and spleen to those in the other tissues lead to the hypothesis that MDA is released from tissues in plasma and trapped from plasma in kidney and spleen. The variations in plasma and erythrocyte were found not to be related to each other.     

Effect of oral methionine and vitamin E on blood lipid peroxidation in vitamin B6 deficient rats

Lipid peroxidation in blood of vitamin B6 deficient rats was significantly increased when compared to pair-fed controls. The observed increased lipid peroxidation in vitamin B6 deficiency was correlated with high levels of lipids, metal ions and low levels of antioxidants, alpha-tocopherol, ascorbic acid and reduced GSH. Supplementation of methionine or vitamin E along with the vitamin B6 deficient diet restored the levels of antioxidants to near normal and also protected against oxidative stress. However plasma TBARS level as well as total lipids were still elevated in M-B6 diet fed rats and normalized in E-B6-d rats.     

Effect of estradiol on lipolytic processes in the blood and adipose tissue of female rats

The effect of estradiol on lipolysis in blood and in adipose tissue of female rat has been investigated. The hormone was administered to the studied animals subcutaneously during 20 days. The lipid mobilizing activity was determined in blood serum according to the four different experimental protocols: test serum--test tissue, test serum--control tissue, control serum--test tissue, and control serum--control tissue. Blood serum concentrations of triglycerides, free fatty acids and glucose, as well as lipolytic activity against exogenous substrate, were determined in addition. Estradiol administration was found to enhance the activity of factors potentiating lipolysis both in the blood and in adipose tissue of female rats, inasmuch as an increase in free fatty acids and triglyceride concentration, and a decrease in glucose concentration were observed during the period of administration of the hormone.     

Correction of lipid peroxidation disorders in experimental traumatic shock using the antioxidant ionol

The level of certain parameters of lipid peroxidation and the activity of lysosome hydrolases were studied on the shock model in rats. It was established that the traumatic shock in the experiment is accompanied by the growth of the level of over-oxidation products (malonic dialdehyde, diene conjugates), the rate of erythrocyte hemolysis as well as by an increase in the hydrolase activity. Administration of ionol (60 mg/kg) inhibits the higher activity of radical-free lipid oxidation, decreases the damage of membrane structure and the metabolism disturbance.     

Effect of riboxine on processes of lipid peroxidation and activity of antioxidant enzymes in thymocytes of rats with radiation injury

The disorders of oxidative homeostasis with accumulation of lipid peroxidation products upon depletion of functional capacity of antioxidant defense in thymus lymphocytes after irradiation in doses of 1.0 and 7.78 Gy were shown. The riboxine injection leads to normalization of balance in prooxidant-antioxidant system (with a decrease of formation of lipid peroxidation and activation of antioxidant enzyme system) in early terms after X-ray exposure.     

Effect of lead on lipid peroxidation in liver of rats

The present study was undertaken to understand the biochemical mechanisms of lead toxicity in liver. We observed a significant accumulation of lead in liver following lead treatment, resulting in accentuation of lipid peroxidation. Concomitant to the increase in lipid peroxidation, the activities of antioxidant enzymes, viz., superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, were significantly inhibited. A decrease in reduced glutathione with a simultaneous increase in oxidized glutathione was observed following lead exposure, resulting in a reduced GSH/GSSG ratio. These results indicate that lead exerts its toxic effects by enhancing peroxidative damage to the membranes, thus compromising cellular functions.     

Effect of cisplatin on lipid peroxidation in blood platelets.

Cisplatin (cis-diamminedichloroplatinum II) at the concentrations of 2-20 micrograms induces non-enzymatic peroxidation of pig platelet lipids. At low concentration (0.1 microgram) it inhibits the enzymatic thrombin-stimulated transformation of platelet endogenous arachidonic acid. This drug also reduces the activities of platelet enzymes: superoxide dismutase and glutathione peroxidase.     

The effect of thyroxine administration on lipid peroxidation in different tissues of rats with hypothyroidism

Thyroid dysfunctions bring about pathological changes in different organs of the body. Findings obtained from in vivo and in vitro studies point out that thyroid hormones have a strong impact on oxidative stress. The present study was conducted to demonstrate how high-dose thyroxin administration for one week affected oxidative damage formed in experimental hypothyroidism. The study was carried out with 30 Spraque-Dawley species male rats. The experimental animals were divided into 3 groups (Group 1, control; Group 2, hypothyroidism; Group 3, hypothyroidism + thyroxine administration). Malondialdehyde (MDA) and glutathione (GSH) levels were determined in cerebral, hepatic and cardiac tissues after the experimental period. MDA and GSH levels in cerebral, hepatic and cardiac tissues of hypothyroidism + thyroxine supplemented group were higher than those in the control and hypothyroidism groups (p<0.001). The same parameters were higher in the control group than those in the hypothyroidism group (p<0.001). The results of the present study show that hypothyroidism reduced the oxidative damage in cerebral, hepatic and cardiac tissues of rats. However, high-dose thyroxine administration in addition to induced hypothyroidism increased oxidative damage in the same tissues and that this damage could not be prevented despite the increase in the antioxidant system activity.     

Effect of alpha-phenyl-N-tert-butylnitrone on diabetes and lipid peroxidation in BB rats.

Oxygen free radicals have been shown to interfere with pancreatic islet beta cell function and integrity, and have been implicated in autoimmune type 1 diabetes. We hypothesized that the spontaneous autoimmune type 1 diabetes of the BB rat would be prevented by in vivo administration of a free-radical spin trap, alpha-phenyl-N-tert-butylnitrone (PBN). Twenty-eight diabetes-prone (BBdp) and 13 non-diabetes-prone (BBn) rats received PBN (10 mg/kg) subcutaneously twice daily, and 27 BBdp and 12 BBn rats received saline as controls. Rats were treated from age 47 +/- 6 days until diabetes onset or age 118 +/- 7 days. PBN caused no growth, biochemical, or hematological side effects. Sixteen control BBdp rats became diabetic (BBd, mean age 77 +/- 6 days) and six demonstrated impaired glucose tolerance (IGT rats). The incidence of diabetes and IGT was not different in PBN-treated BBdp rats. Saline-treated rats showed no differences in pancreatic malondialdehyde (MDA) contents of BBd, IGT rats, and the BBdp that did not develop diabetes, versus BBn rats (2.38 +/- 0.35 nmoL/g). Among rats receiving PBN, BBn had lower pancreatic MDA than BBd and IGT rats (1.38 +/- 0.15 vs. 1.88 +/- 0.15 and 2.02 +/- 0.24 nmoL/g, p < 0.05), but not than BBdp rats (1.78 +/- 0.12 nmoL/g, ns). BBn rats receiving PBN also had lower pancreatic MDA than the saline controls (p < 0.05). Thus, PBN is remarkably nontoxic and is able to decrease MDA in the absence of the autoimmune process, but does not prevent diabetes. A combination of PBN with other complementary antioxidant agents may hold better promise for disease prevention.